XPS 420 Dual Monitors

I have a XPS 420 with an ATI Radeon HD 3650. My question is what would be the best way to hook up dual 22" monitors? I've seen some computers with a "Y" from the DVI to two monitors or should I connect one monitor to the DVI and the other to the HDMI with an adapter to DVI?

My video card does not have two DVI connectors, instead it has a DVI, HDMI and a DisplayPort.

What are the advantages to hooking on to the HDMI instead of a "Y" connector.

I watched all those "help" videos on You Tube and weren't all that much help. One guy was just bragging about his system and how much RAM he was going to buy. Another one just showing off his dual monitors in the dark, a few were trying to help if you already have two DVI connectors, but you wouldn't be needing help if you have two DVI connectors, what are they stupid? JUst thought I'd share it was quite funny.

I wanted to get with one of the guys at the company I work for. He has two monitors and I know he has a "Y" connector, because I can see the back of his computer and he has the screen in extended mode. As for the DisplayPort to DVI, yes they make one, in fact Dell has the best price for it.